Method for Increasing Oilfield Recovery Rates and Oil Production

ABSTRACT

The invention relates to the oil-extracting industry and is intended for increasing petroefficiency of an oilfield and petroleum production in oily and depleted oil layers. The invention may be also applied in gas-production industry. It provides for increasing petroefficiency of an oilfield and petroleum production due to use of tidal stretching and compression of the earth&#39;s crust owing to solar-lunar influences on it. The essence of the invention: periodic external physical influences are exerted on an oil-bearing layer depending on solar-lunar influences on the earth&#39;s crust. Thus the physical influences are applied in a zone of oil-bearing layer during compression of the earth&#39;s crust at solar-lunar ebbs. They take into account the set of amplitudes of solar-lunar influences.

The invention relates to the oil-extracting industry and is intended for increasing petroefficiency of an oilfield and petroleum production in oily and depleted oil layers.

The invention may be also applied in gas-production industry.

PRIOR ART

There is a known device for wave processing of a layer using a method that includes influencing the layer with elastic oscillations while flooding a working fluid (see the Russian Federation patent No. 1727431, Cl. E 21 B 43/00, 1996). The drawback of the known method is that the fluid injected in wells under a high pressure during expansion of cracks and volumes of the earth's crust easily fills in the empty spaces thus expanding the cracks and interferes with process of absorption of oil from pores of layers in cracks that reduces the oil/water ratio and the petroefficiency.

There is a known phenomenon of periodic lunar-solar tidal deformations influencing the fracturing and periodic variations of amplitudes of mechanical oscillations inside the earth's crust, registered in wells depth ranging from 300 to 1000 m (V. A. Gavrilov. Creating a system of wells geoacoustic observations. Scientific report of the Kamchatka Centre of Science of the Far East department of the Russian Academy of Science, Institute of Volcanology. Petropavlovsk-Kamchatski, 2001).

The maximal energy of acoustic noise, as well as the stabilization of filtrational properties, correspond to stretching of the earth's crust, that is to say during an inflow.

It is also known that the vibrations compress the strained environment (earth's crust) thus they are operating in an antiphase to the expansion of the earth's crust during an inflow (K. M. Mirzoev, etc., <<Influence of mechanical vibrations on seismicity>>, DAN USSR, vol. 313, No1, Geophysics, 1990, pp. 78-83).

It is known that lunar flow amplitude is some times higher that that of the solar flow, and their periods not always coincide, while and the amplitude level of geoacoustic emission more strongly depends on lunar influences.

The method most close to the technical essence of the offered technical decision is the method for increasing petroefficiency of an oilfield and petroleum production, including periodic external physical influences on an oil-bearing layer depending on solar-lunar influences on the earth's crust (see, e.g., Russian Federation patent No 2046936, 27.10.1995).

There is a known method for increasing petroefficiency of an oilfield and petroleum production where the influence on an oil-bearing layer is due to pumping a fluid (Russian Federation patent No 2095550, E21B 43/00, 1997).

However the above method has a drawback consisting in that pumping a fluid is continuous during both expansion and compression of earth's crust (inflow and ebbs), that is the method is not taking into account the tidal gravity movement. Therefore, during expansion of cracks the injected fluid fills in cracks thus interfering with extraction of oil from pores in cracks.

The method most close to the offered technical essence to the offered technical decision is the method for activating the petroefficiency, including periodic external physical influence on a layer (see EB No001474, Cl. E21B 43/00, 2000). As the external influence the known method uses a vibration action on an oil layer from the ground surface.

The known method provides a choice of points of increased strain of the earth's crust where the vibration action takes place. It has no direct relation to increase of petroefficiency of a layer, however it concerns the process of relieving the strain in these points for preventing possible earthquakes.

Thus the producing wells and salvage sumps or layers may be away from these points of strain that reduces the effect of vibration action on a layer.

Locating the points of strain in the earth's crust is involve high costs and a high degree of immediacy as these points continuously change their location.

The known method does not take into account, that during a vibration action there is an amplification of compression of the earth's crust (compression of cracks), and after the vibration action there is an expansion of the earth's crust, where the processes of expansion and compression of cracks due to vibration actions are not synchronized with similar stretching and compression due to lunar-solar flow therefore the effect from vibration actions is either reduced, or disappears completely, depending on the misphasing degree.

DISCLOSURE OF THE INVENTION

The task of the present design is to increase petroefficiency of an oilfield and petroleum production due to more efficient use of tidal stretching and compression of the earth's crust due to solar-lunar influences on the last.

The result of the offered decision is obtained by creating a method for increasing petroefficiency of an oilfield and petroleum, including external periodic physical influences on an oil-bearing layer depending on solar-lunar influences on the earth's crust where according to the invention the physical influences are applied in a zone of oil-bearing layer during compression of the earth's crust at solar-lunar ebbs and taking into account the set of amplitudes of solar-lunar influences. The invention is also characterized by that the external influences are carried out or by vibration, and/or by pumping a fluid.

The external influences may be of any nature: magnetic, ultrasonic, etc.

Gravitational influences on the earth's crust take into account all the gravitational influences, namely, connected with changes of atmospheric pressure upon surfaces of the ground, with changes of a gravitational field in connection with tectonic movement of the earth's crust, with changes of gravitational field and deformations of a terrestrial surface due to a known natural dilatation (expansion) of large volumes of the earth's crust before strong earthquakes,

as well as weak gravitational influence of other planets on the earth's crust creating additional gravitational fields having the significance at the equilibrium state of gravitational field of the earth when it it is close to its average value (an average zero line at lunar-solar and other influences).

In the offered method the extraction of oil from pores of a layer in cracks takes place during expansion of cracks as a result of lunar-solar inflow and dilatation of the earth's crust after a vibration action. During this period it is not necessary to fill in a crack with pumped fluid.

After the period of expansion of cracks and extraction of oil from pores comes to an end and the compression of cracks as a result of lunar-solar ebbs and vibration actions begins, it is necessary to npump a fluid in producing wells for speeding up the oil displacement.

The Best Embodiment

In the offered method during expansion of cracks as a result of lunar-solar flow and dilatation of the earth's crust after a vibration action there is an extraction (drawing-off) of oil from pores of a layer into cracks. During this period it is not necessary to fill in a crack with pumped liquid.

After the period of expansion of cracks and extraction of oil from pores comes to an end and compression of cracks begins as a result of lunar-solar ebbs and vibration actions, it is necessary to pump the fluid into the producing wells to accelerate the oil displacement.

The offered method for increasing petroefficiency of an oilfield and petroleum production may be exercised as follows.

The preliminary influences are applied in the territory of a deposit where the petroleum production occurs.

For this purpose at least one vibrator is placed in the territory. Its placement is chosen so that to cover with maximal or uniform vibrations all the area of a layer or any part of it. Thus the vibrators are placed within the limits of occurrence of oil.

Then vibration is produced in the area of occurrence of oil during the period of compression of the earth's during a lunar-solar ebb.

Elastic vibrations will penetrate inside the firm ground and reach the area of occurrence of oil as it is known that the stored signals due to the influence are registered at a distances of up to 100 kilometers and more.

Together with vibration it is possible to pump fluid at least in one well.

Pumping the fluid may be used as an independent external influence during compression of the earth's crust at a lunar-solar ebb.

When cracks expand there is a mass exchange between oil in pores of a layer and the fluid pumped in the cracks.

During the process of compression of the cracks filled with oil and pumping of fluid in producing wells the oil displaces through cracks and other channels to producing wells.

Pumping the fluid in the pumping wells boosts the replacement of oil from cracks and accelerates its delivery to producing wells, while the gradual replacement of oil by fluid in poral space prevents residual deformations and sag of the earth's crust on a surface of the ground that is important for buildings and constructions. In the offered method the influence is exerted in view of cumulative amplitude of solar-lunar influences.

The vibrating influences in the offered method do not leave residual deformations in the earth's crust and on the surface of the ground because due to dilatation the additional deformations which have arisen due to vibrations are reversible. In conditions of natural stationary intense state of the earth's crust and external influences, e.g. vibration actions of elastic character, the duration of dilatation corresponds to the time of influence (K. M. Mirzoev et al. Influence of mechanical vibrations on seismicity, DAN USSR, volume 313, No 1, Geophysics, 1990, pp. 78-83).

Therefore the influences are effected daily during compression of the earth's crust on the surface of the ground or in wells, their duration is up to 12 hours.

INDUSTRIAL APPLICABILITY

The offered method is suitable for oil, as well for gas deposits having any structure of deposit and collector, as well as the structure of geological material. The method uses powerful natural tidal phenomena of the earth's crust which do not require additional financial and resource expenses, while the effect of increasing the petroefficiency exceeds all known methods of increasing the extraction of hydrocarbonic raw material because the powerful natural phenomena, used in the present invention are second to none.

The side benefits of the method are: ecological safety and possibility of reducing the expensive drilling of new producing wells. 

1. A method for increasing petroefficiency of an oilfield and petroleum production, including external periodic physical influences on an oil-bearing layer depending on solar-lunar influences on the earth's crust, whereas the physical influences is produced in the area of occurrence of oil during the period of compression of the earth's during a lunar-solar ebb in view of cumulative amplitude of solar-lunar influences.
 2. A method for increasing petroefficiency of an outfield and petroleum production, as claimed in claim 1 whereas the external influences are produced by vibration.
 3. A method for increasing petroefficiency of an oilfield and petroleum production, as claimed in claim 1 whereas the external influences are produced by pumping a fluid. 